path: root/voctocore/lib/video/mix.py

#!/usr/bin/python3
import logging
from gi.repository import Gst
from enum import Enum

from lib.config import Config

class CompositeModes(Enum):
    fullscreen = 0
    side_by_side_equal = 1

class VideoMix(object):
    log = logging.getLogger('VideoMix')

    mixingPipeline = None

    caps = None
    names = []

    compositeMode = CompositeModes.fullscreen
    sourceA = 0
    sourceB = 1

    def __init__(self):
        self.caps = Config.get('mix', 'videocaps')

        self.names = Config.getlist('sources', 'video')
        self.log.info('Configuring Mixer for %u Sources', len(self.names))

        pipeline = """
            videomixer name=mix !
            {caps} !
            textoverlay text=mixer halignment=left valignment=top ypad=175 !
            intervideosink channel=video_mix
        """.format(
            caps=self.caps
        )

        for idx, name in enumerate(self.names):
            pipeline += """
                intervideosrc channel=video_{name}_mixer !
                {caps} !
                videoscale !
                capsfilter name=caps_{idx} !
                mix.
            """.format(
                name=name,
                caps=self.caps,
                idx=idx
            )

        self.log.debug('Creating Mixing-Pipeline:\n%s', pipeline)
        self.mixingPipeline = Gst.parse_launch(pipeline)

        self.log.debug('Initializing Mixer-State')
        self.updateMixerState()

        self.log.debug('Launching Mixing-Pipeline:\n%s', pipeline)
        self.mixingPipeline.set_state(Gst.State.PLAYING)

    def updateMixerState(self):
        if self.compositeMode == CompositeModes.fullscreen:
            self.updateMixerStateFullscreen()

        if self.compositeMode == CompositeModes.side_by_side_equal:
            self.updateMixerStateSideBySideEqual()

    def updateMixerStateFullscreen(self):
        self.log.info('Updating Mixer-State for Fullscreen-Composition')

        noScaleCaps = Gst.Caps.from_string('video/x-raw')

        for idx, name in enumerate(self.names):
            alpha = int(idx == self.sourceA)

            self.log.debug('Setting Mixerpad %u to x/y=0 and alpha=%0.2f', idx, alpha)
            mixerpad = self.mixingPipeline.get_by_name('mix').get_static_pad('sink_%u' % idx)
            mixerpad.set_property('alpha', alpha )
            mixerpad.set_property('xpos', 0)
            mixerpad.set_property('ypos', 0)

            self.log.debug('Resetting Scaler %u to non-scaling', idx)
            capsfilter = self.mixingPipeline.get_by_name('caps_%u' % idx)
            capsfilter.set_property('caps', noScaleCaps)

    def getInputVideoSize(self):
        caps = Gst.Caps.from_string(self.caps)
        struct = caps.get_structure(0)
        _, width = struct.get_int('width')
        _, height = struct.get_int('height')

        return width, height

    def updateMixerStateSideBySideEqual(self):
        self.log.info('Updating Mixer-State for Side-by-side-Equal-Composition')

        width, height = self.getInputVideoSize()
        gutter = int(width / 100)

        self.log.debug('Video-Size parsed as %u/%u, Gutter calculated to %upx', width, height, gutter)

        targetWidth = int((width - gutter) / 2)
        targetHeight = int(targetWidth / width * height)

        ycenter = (height - targetHeight) / 2
        xa = 0
        xb = width - targetWidth

        scaleCaps = Gst.Caps.from_string('video/x-raw,width=%u,height=%u' % (targetWidth, targetHeight))
        noScaleCaps = Gst.Caps.from_string('video/x-raw')

        for idx, name in enumerate(self.names):
            mixerpad = self.mixingPipeline.get_by_name('mix').get_static_pad('sink_%u' % idx)

            if idx == self.sourceA:
                x = xa
                y = ycenter
                caps = scaleCaps
                alpha = 1

                self.log.debug('Setting Mixerpad %u to x/y=%u/%u and alpha=%0.2f', idx, x, y, alpha)
                self.log.debug('Setting Scaler %u to %u/%u', idx, targetWidth, targetHeight)

            elif idx == self.sourceB:
                x = xb
                y = ycenter
                caps = scaleCaps
                alpha = 1

                self.log.debug('Setting Mixerpad %u to x/y=%u/%u and alpha=%0.2f', idx, x, y, alpha)
                self.log.debug('Setting Scaler %u to %u/%u', idx, targetWidth, targetHeight)

            else:
                x = 0
                y = 0
                caps = noScaleCaps
                alpha = 0

                self.log.debug('Setting Mixerpad %u to x/y=%u/%u and alpha=%0.2f', idx, x, y, alpha)
                self.log.debug('Resetting Scaler %u to non-scaling', idx)

            mixerpad.set_property('alpha', alpha)
            mixerpad.set_property('xpos', x)
            mixerpad.set_property('ypos', y)

            capsfilter = self.mixingPipeline.get_by_name('caps_%u' % idx)
            capsfilter.set_property('caps', caps)

    def setVideoA(self, source):
        # swap if required
        if self.sourceB == source:
            self.sourceB = self.sourceA

        self.sourceA = source
        self.updateMixerState()

    def setVideoB(self, source):
        # swap if required
        if self.sourceA == source:
            self.sourceA = self.sourceB

        self.sourceB = source
        self.updateMixerState()

    def setCompositeMode(self, mode):
        self.compositeMode = mode
        self.updateMixerState()